Method and treatment composition for imparting durable antimicrobial properties to carpet

ABSTRACT

Methods and treatment compositions for imparting durable antimicrobial properties to carpet are provided. The method includes applying a composition comprising a first antimicrobial compound and a fluoropolymer to the carpet substrate. The carpet substrate may be steamed thereafter. The treatment composition may comprise a fluoropolymer, an antimicrobial compound selected from a group consisting of zinc pyrithione, a silver-containing antimicrobial compound and combinations thereof, and a foamer. Carpet products treated with the treatment composition or treated in accordance with the methods are also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/683,914, filed on Jan. 7, 2010, now U.S. Pat. No. 8,586,145 issued onNov. 19, 2013, and claims the benefit of U.S. Provisional PatentApplication No. 61/143,108, filed on Jan. 7, 2009. These applicationsare incorporated herein by reference in their entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

This invention relates generally to the field of carpets, and moreparticularly to carpets having antimicrobial properties.

Various antimicrobial treatments are currently used in the carpetindustry to impart antimicrobial properties to the manufactured carpet.The most popular methods include topical applications and dry cureapplications of antimicrobial compounds to the carpet substrate.However, conventional antimicrobial treatment methods used in theindustry have damaging effects on carpet performance attributes suchflame resistance, soil resistance, and color fastness. For example, manyantimicrobial compounds, when applied topically to a carpet substratefollowing a fluoropolymer treatment and prior to drying in a dryer, willincrease the flammability of the carpet.

BRIEF SUMMARY OF THE INVENTION

In one aspect, a method of treating a carpet substrate is provided. Themethod may include applying a composition comprising a firstantimicrobial compound and a fluoropolymer to the carpet substrate.

In another aspect, a method of treating a carpet substrate is providedthat comprises applying a first antimicrobial compound and afluoropolymer to the carpet substrate, and thereafter steaming thecarpet substrate.

In another aspect, a treatment composition is provided for impartingdurable antimicrobial properties to a carpet. The treatment compositionmay comprise a fluoropolymer; an antimicrobial compound selected from agroup consisting of zinc pyrithione, a silver-containing antimicrobialcompound and combinations thereof; and a foamer.

Carpet products treated with the treatment composition or treated inaccordance with the methods are also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram, illustrating a method of imparting durableantimicrobial properties to a carpet in accordance with one or moreembodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Methods have been developed to provide a carpet with durableantimicrobial properties using modern continuous application equipmentwithout negating or diminishing other desirable performancecharacteristics of the carpet. The present method can impartantimicrobial properties to a variety of carpet materials comprisingvarious types of fibers including, but not limited to, nylon, polyester,wool, polypropylene, PTT, silk, cotton, rayon, acetate, and combinationsthereof.

It has been discovered that durable antimicrobial properties may beimparted to a carpet in a continuous, single-step treatment with afluoropolymer without diminishing combined performance attributes. Inone embodiment, one or more antimicrobial compounds are applied via foamin an exhaust application step utilizing a foam applicator such as aKüsters Fluicon™ foam applicator (Andritz Küsters GmbH) immediatelybefore feeding the carpet into a steamer. Once the carpet exits thesteamer, it typically is washed and extracted prior to entrance into thedryer.

One embodiment of the method is illustrated in FIG. 1. The treatmentprocess 10 may be readily integrated with a continuous manufacturingprocess which feeds a carpet substrate through various in-line processequipment, such as is known in the art. In treatment process 10, thecarpet substrate may be first fed through a treatment apparatus 12, thenimmediately through a steamer 14, then through a washing apparatus 16and a dryer 18. In the treatment apparatus 12, the carpet substrate maybe subjected to foam treatment with a foam comprising one or moresuitable antimicrobial compounds and a fluoropolymer. Variousantimicrobial compounds may be used including, but not limited to,Ultrafresh™ DM-50, commercially available from Thompson ResearchAssociates (Canada), Alphasan™ RC-5000, commercially available fromMilliken Chemical (Spartanburg, S.C.), Zinc Omadine™ and Reputex™20,commercially available from Arch Chemical (Norwalk, Conn.). In oneembodiment, the antimicrobial compound is zinc pyrithione and/orAlphaSan™, which is an antimicrobial compound available from MillikenChemicals (Spartanburg, S.C.). Alphasan is believed to be a zirconiumphosphate-based ceramic ion-exchange resin containing silver.

In a preferred embodiment, a treatment composition is applied to thecarpet substrate. The treatment composition may be in the form of a foamand may comprise a fluoropolymer, a foamer, magnesium sulfate liquid,zinc pyrithione, and a zirconium phosphate-based ceramic ion-exchangeresin containing silver. Various fluoropolymers may be used including,but not limited to, Centapel EFP-7, commercially available from CentaurTechnologies (Dalton, Ga.), Unidyne™ TG 580, TG 581, TG 2211 and TG2511, all of which are commercially available from Daikin America, Inc.(Orangeburg, N.Y.); PM 1396, PM 1399, PM 1400 and PM 1451, all of whichare commercially available from 3M Specialty Chemicals Division (St.Paul, Minn.); Capstone™ RCP and Capstone™ TUC, both of which arecommercially available from DuPont (Wilmington, Del.). In someembodiments, an aqueous composition of the treatment compositioncontains 3M PM 1399 which is commercially available from 3M InnovativeProducts (Minneapolis, Minn.). The fluoropolymer may be provided in anamount of about 0.05 to about 20% owg (on the weight of the goods), orabout 0.4% owg. The magnesium sulfate liquid may be provided in anamount of about 0.1 to about 20% owg, or about 2.0% owg.

Various foamers may be used including, but not limited to, CentafoamYEP-10, which is available from Centaur Technologies. The foamer maycomprise about 0.1 to about 100 g/l of the treatment composition orabout 4.0 g/l of the treatment composition. The treatment may alsocomprise Centafresh, which is available from Centaur Technologies, in anamount of about 7 g/sq.yd. of carpet substrate. The treatmentcomposition may also comprise various pH adjusting additives such asSystem 404, which is available from Phoenix Chemical (Calhoun, Ga.). ThepH of the treatment composition may be about 2.0 to about 12.0, or about2.1.

The treatment composition may comprise various antimicrobialcompositions including, but not limited to, zinc pyrithione andsilver-containing antimicrobial compounds. The zinc pyrithione maycomprise about 1 to about 50,000 ppm of the treatment composition orabout 500 ppm of the treatment composition. Various silver-containingantimicrobial compounds may be used including Alphasan, which isavailable from Milliken Chemicals (Spartanburg, S.C.). Thesilver-containing antimicrobial compound may comprise about 1 to about50,000 ppm of the treatment composition or about 200 ppm of thetreatment composition.

In one embodiment, after the carpet substrate is treated with thefluoropolymer and antimicrobial compound composition, the carpetsubstrate is immediately steamed in the steamer 14. The carpet substrateis then rinsed and extracted by the washing apparatus 16 and dried inthe dryer 18.

It has been observed that treating the carpet substrate with afluoropolymer and an antimicrobial compound in a single stage results inunexpected synergistic effects and improved performance properties. Inparticular, the treated carpet demonstrates durable antimicrobialproperties, excellent stain repellency and color fastness withoutdiminished flame resistance.

EXAMPLES

In each of the following examples tufted filament polyester carpet dyedwith disperse dyes were from Beaulieu of America (Chatsworth, Ga.) wereused for the sample carpet substrates.

The following chemicals were also used in the examples: Zinc Pyrithione,an antimicrobial compound available from Arch Chemicals (Norwalk,Conn.); Alphasan, a silver containing antimicrobial compound availablefrom Milliken Chemicals (Spartanburg, S.C.); Invasan RCD, asugar-derived freshener available from Huntsman Textile Effects(Switzerland); Centafresh, available from Centaur Technologies; PM 1399,a fluoropolymer available from 3M Innovative Products (Minneapolis,Minn.); Centafoam YEP-10, a foamer available from Centaur Technologies;Centex Binder, a binding agent available from Centaur Technologies;System 404, available from Phoenix Chemical (Calhoun, Ga.); andmagnesium sulfate liquid.

Example One

A foam was prepared containing 3M PM 1399 at 0.4% owg (on the weight ofthe goods), magnesium sulfate liquid at 2.0% owg, Centafoam YEP-10 at4.0 g/l, Centafresh at 7 g/sq. yd. The pH of the foam was adjusted to2.1 with System 404. The foam solution was applied to a polyesterfilament carpet at 100% wet pick up. The carpet was then subjected tosteam for 60 seconds then rinsed and extracted prior to entrance intothe dryer.

Example Two

A polyester filament carpet was treated in a two step applicationprocess. The first step was an exhaust application at 100% wet pick upvia foam. The solution used in the first step contained 3M PM 1399 at0.4% owg (on the weight of the goods), magnesium sulfate liquid at 2.0%owg, Centafoam YEP-10 at 4.0 g/l, Centafresh at 7 g/sq.yd. The pH of thefoam was adjusted to 2.1 with System 404. The foam solution was appliedto the fiber and then the carpet was subjected to steam for 60 secondsthen rinsed and extracted.

After extraction the carpet was treated with the second step. The secondstep was an 8% wet pick up topical foam application. The solution usedin the second step contained Alphasan at 1000 ppm with Centafoam YEP-10at 4.0 g/l. The solution was applied to the fiber by topical foam andthen the carpet was placed into an oven at 140 degrees C. until dry.

Example Three

A polyester filament carpet was treated in a two step applicationprocess. The first step was an exhaust application at 100% wet pick upvia foam. The solution used in the first step contained 3M PM 1399 at0.4% owg (on the weight of the goods), magnesium sulfate liquid at 2.0%owg, Centafoam YEP-10 at 4.0 g/l, Centafresh at 7 g/sq.yd. The pH of thefoam was adjusted to 2.1 with System 404. The foam solution was appliedto the fiber and subjected to steam for 60 seconds then rinsed andextracted.

After extraction the carpet was treated with the second step. The secondstep was an 8% wet pick up topical foam application. The solution usedin the second step contained Alphasan at 1000 ppm with 0.5% owg CentexBinder and Centafoam YEP-10 at 4.0 g/l. The solution was applied to thefiber by topical foam and then the carpet was placed into an oven at 140degrees C. until dry.

Example Four

A polyester filament carpet was treated in a two step applicationprocess. The first step was an exhaust application at 100% wet pick upvia foam. The solution used in the first step contained 3M PM 1399 at0.4% owg (on the weight of the goods), magnesium sulfate liquid at 2.0%owg, Centafoam YEP-10 at 4.0 g/l, Centafresh at 7 g/sq.yd. The pH of thefoam was adjusted to 2.1 with System 404. The foam solution was appliedto the fiber and then the carpet was subjected to steam for 60 secondsthen rinsed and extracted.

After extraction the carpet was treated with the second step. The secondstep was an 8% wet pick up topical foam application. The solution usedin the second step contained Zinc Pyrithione at 500 ppm and CentafoamYEP-10 at 4.0 g/l. The solution was applied to the fiber by topical foamand the carpet was then placed into an oven at 140 degrees C. until dry.

Example Five

A polyester filament carpet was treated in a two step applicationprocess. The first step was an exhaust application at 100% wet pick upvia foam. The solution used in the first step contained 3M PM 1399 at0.4% owg (on the weight of the goods), magnesium sulfate liquid at 2.0%owg, Centafoam YEP-10 at 4.0 g/l, Centafresh at 7 g/sq.yd. The pH of thefoam was adjusted to 2.1 with System 404. The foam solution was appliedto the fiber and the carpet was subjected to steam for 60 seconds thenrinsed and extracted.

After extraction the carpet was treated with the second step. The secondstep was an 8% wet pick up topical foam application. The solution usedin the second step contained Zinc Pyrithione at 500 ppm with 0.5% owgCentex Binder and Centafoam YEP-10 at 4.0 g/l. The solution was appliedto the fiber by topical foam and the carpet was then placed into an ovenat 140 degrees C. until dry.

Example Six

A polyester filament carpet was treated in a two step applicationprocess. The first step was an exhaust application at 100% wet pick upvia foam. The solution used in the first step contained 3M PM 1399 at0.4% owg (on the weight of the goods), magnesium sulfate liquid at 2.0%owg, Centafoam YEP-10 at 4.0 g/l, Centafresh at 7 g/sq.yd. The pH of thefoam was adjusted to 2.1 with System 404. The foam solution was appliedto the fiber and the carpet was subjected to steam for 60 seconds thenrinsed and extracted.

After extraction the carpet was treated with the second step. The secondstep was an 8% wet pick up topical foam application. The solution usedin the second step contained Invasan at 500 ppm and Centafoam YEP-10 at4.0 g/l. The solution was applied to the fiber by topical foam and thecarpet was then placed into an oven at 140 degrees C. until dry.

Example Seven

A polyester filament carpet was treated in a two step applicationprocess. The first step was an exhaust application at 100% wet pick upvia foam. The solution used in the first step contained 3M PM 1399 at0.4% owg (on the weight of the goods), magnesium sulfate liquid at 2.0%owg, Centafoam YEP-10 at 4.0 g/l, Centafresh at 7 g/sq.yd. The pH of thefoam was adjusted to 2.1 with System 404. The foam solution was appliedto the fiber and the carpet was subjected to steam for 60 seconds thenrinsed and extracted.

After extraction the carpet was treated with the second step. The secondstep was an 8% wet pick up topical foam application. The solution usedin the second step contained Invasan at 500 ppm with 0.5% owg CentexBinder and Centafoam YEP-10 at 4.0 g/l. The solution was applied to thefiber by topical foam and the carpet was then placed into an oven at 140degrees C. until dry.

Example Eight

A polyester filament carpet was treated in a two step applicationprocess. The first step was an exhaust application at 100% wet pick upvia foam. The solution used in the first step contained 3M PM 1399 at0.4% owg (on the weight of the goods), magnesium sulfate liquid at 2.0%owg, Centafoam YEP-10 at 4.0 g/l, Centafresh at 7 g/sq.yd. The pH of thefoam was adjusted to 2.1 with System 404. The foam solution was appliedto the fiber and the carpet was subjected to steam for 60 seconds thenrinsed and extracted.

After extraction the carpet was treated with the second step. The secondstep was an 8% wet pick up topical foam application. The solution usedin the second step contained Alphasan at 200 ppm, Zinc Pyrithione at 500ppm and Centafoam YEP-10 at 4.0 g/l. The solution was applied to thefiber by topical foam and the carpet was then placed into an oven at 140degrees C. until dry.

Example Nine

A polyester filament carpet was treated in a two step applicationprocess. The first step was an exhaust application at 100% wet pick upvia foam. The solution used in the first step contained 3M PM 1399 at0.4% owg (on the weight of the goods), magnesium sulfate liquid at 2.0%owg, Centafoam YEP-10 at 4.0 g/l, Centafresh at 7 g/sq.yd. The pH of thefoam was adjusted to 2.1 with System 404. The foam solution was appliedto the fiber and the carpet was subjected to steam for 60 seconds thenrinsed and extracted.

After extraction the carpet was treated with the second step. The secondstep was an 8% wet pick up topical foam application. The solution usedin the second step contained Alphasan at 200 ppm, Zinc Pyrithione at 500ppm with 0.5% owg Centex Binder and Centafoam YEP-10 at 4.0 g/l. Thesolution was applied to the fiber by topical foam and the carpet wasthen placed into an oven at 140 degrees C. until dry.

Example Ten

A foam was prepared containing 3M PM 1399 at 0.4% owg (on the weight ofthe goods), magnesium sulfate liquid at 2.0% owg, Centafoam YEP-10 at4.0 g/l, Centafresh at 7 g/sq.yd., Alphasan at 200 ppm, Zinc Pyrithioneat 500 ppm. The pH of the foam was adjusted to 2.1 with System 404. Thefoam solution was applied to the carpet and the carpet was subjected tosteam for 60 seconds then rinsed and extracted prior to being placedinto the dryer.

Example Eleven

A foam was prepared containing 3M PM 1399 at 0.4% owg (on the weight ofthe goods), magnesium sulfate liquid at 2.0% owg, Centafoam YEP-10 at4.0 g/l, Centafresh at 7 g/sq.yd., Invasan at 1,000 ppm. The pH of thefoam was adjusted to 2.1 with System 404. The foam solution was notapplied to the carpet due to coagulation and precipitation.

Example Twelve

A polyester filament carpet sample was maintained non-treated for use asa control.

Example Thirteen

All test samples of EXAMPLES 1-12 were subjected to American Associationof Textile Chemists and Colorists (AATCC) test method 138, undergoing 10cycles wash/extractions. The samples were further subjected to AATCCtest method 123, a pill test for flammability, a repellency test, and a40 hour light fastness test.

TABLE ONE RESULTS AATCC AATCC AATCC 40 hrs 123 Part 123 Part 123 PartPill Light Trial # I II III Test Repellency Fastness Example #1 FailFail Fail Pass Pass Pass Example #2 Fail Fail Fail Pass Pass PassExample #3 Fail Pass Fail Fail Pass Pass Example #4 Fail Fail Fail PassPass Pass Example #5 Pass Pass Fail Fail Pass Fail Example #6 Fail FailFail Pass Pass Pass Example #7 Fail Fail Fail Fail Pass Pass Example #8Fail Fail Fail Pass Pass Pass Example #9 Pass Pass Fail Fail Pass FailExample #10 Pass Pass Pass Pass Pass Pass Example #11 NA NA NA NA NA NAExample #12 Fail Fail Fail Pass Fail Pass

As demonstrated in TABLE ONE, a synergistic effect exists withco-exhaustion of Zinc Pyrithione, Alphasan, Centafresh, PM 1399, andCentafoam YEP-10. Superior results were achieved with this unexpecteddiscovery. Excellent antibacterial/antifungal results, repellency, andlight fastness were achieved without causing flammability failures.

Many variations exist for the conditions previously outlined in theexamples. Those skilled in the art recognize the many variations forequipment and conditions involving exhaust and topical application ofchemical treatments. Previously outlined descriptions are supplied asexamples and are not meant to be exclusive.

We claim:
 1. A carpet product having antimicrobial propertiescomprising: a carpet substrate treated with a foam treatment compositionin a single-step application, the foam treatment comprises afluoropolymer, zinc pyrithione, a magnesium sulfate liquid and asilver-containing antimicrobial compound, wherein the carpet productpasses AATCC Test
 123. 2. The carpet product of claim 1, wherein themagnesium sulfate liquid is present in an amount of about 0.1 to about20% owg.
 3. The carpet product of claim 1, wherein the magnesium sulfateliquid is present in an amount of about 2.0% owg.
 4. The carpet productof claim 1, wherein the fluoropolymer is present in an amount of about0.05 to about 20% owg.
 5. The carpet product of claim 1, wherein thefluoropolymer is present in an amount of about 0.4% owg.
 6. The carpetproduct of claim 1, wherein the foam treatment composition furthercomprises a pH adjusting additive and the treatment composition has a pHof about 2.0 to about
 12. 7. The carpet product of claim 1, wherein thesilver-containing antimicrobial compound comprises a zirconiumphosphate-based ceramic ion-exchange resin containing silver.
 8. Thecarpet product of claim 1, wherein the foam treatment compositioncomprises about 500 ppm of the zinc pyrithione and about 200 ppm of thesilver-containing antimicrobial compound.